The invention pertains to an internal combustion engine with a connecting means for connecting a first section to a second section of a wire harness on a cylinder head housing. The invention further relates to a process for installing such a harness.
In an internal combustion engine, the fuel is injected into the combustion chamber through an injector. An electronic controller transmits the appropriate actuating signals, which determine the switching state of the injector. The signals are transmitted over a wire harness. Because the injector is located inside the cylinder head housing, the wire harness must pass through the cylinder head housing. This pass-through is critical, because the cylinder head housing must be sealed to prevent the leakage of lubricant and fuel into the environment. The engine vibrations also subject the wire harness to mechanical stress at the pass-through point.
EP 0 454 895 B1 describes a pass-through for a wire harness on a cylinder head. The wire harness is embedded in a seal, which is mounted between the cylinder head and the boot. In another embodiment, the individual wires of the wire harness are pushed through bores in the seal. The problem here is that the wire harness can suffer mechanical damage as a result of excessive tightening torque when the boot is attached to the cylinder head.
DE 197 34 970 A1 describes a central plug, which is screwed into the cylinder head housing of the internal combustion engine. The wire harness leading from the electronic controller to the injector consists of a first section and a second section. The first section extends from the electronic controller to a “counterplug”. The second section of the wire harness extends through the interior of the cylinder head housing from the central plug to the injector. By means of a seal, the central plug seals the cylinder head so that no lubricant or fuel can leak out. The problem with this plug-bushing concept is that the manufacturing of the parts themselves is expensive and the fabrication of the first section of the wire harness with the counterplug is complicated. Another difficulty is that the service life of a plug-bushing concept (3,000 hours of operation) is much shorter than the service life of a large diesel engine (more than 20,000 hours of operation). The plug-bushing concept therefore cannot be used in large diesel engines.